my samsung wa55cg7100aw washer just shows nd and a lock symbol and won't start, what's going on?

Diagnosis

The "nd" error code combined with the lock symbol on your Samsung WA55CG7100AW indicates that the Child Lock feature has been accidentally activated. When this mode is engaged, the control panel is electronically disabled to prevent children from changing settings or starting the machine. The "nd" specifically refers to a "No Detergent" or "Not Determined" state where the machine refuses to initiate the cycle because the control board is ignoring all user inputs, including the Start/Pause button. You can confirm this is a software lock rather than a hardware failure by attempting to press any button on the console. If the machine beeps but the display does not change and the lock icon remains steady, the Child Lock is active. This is a common occurrence on the WA55 series because the buttons for Child Lock are located in a high-traffic area of the control panel, making them easy to press accidentally while loading laundry or cleaning the top of the machine.

How to Fix It

To deactivate the Child Lock and restore full functionality to your washer, follow these precise steps:

1. Ensure the washer is powered on. If the display is blank, press the Power button first.
2. Locate the Spin Speed and Soil Level buttons on the control panel. These are typically positioned side-by-side or in close proximity.
3. Press and hold both the Spin Speed and Soil Level buttons simultaneously. You must apply firm, steady pressure to both buttons at the exact same time.
4. Maintain this hold for a full 3 to 5 seconds. Do not release the buttons until you hear a chime or see the lock icon disappear from the LED display.
5. Verify that the "nd" code has vanished and the display now shows the default cycle time or the "Ready" state.
6. Press the Start/Pause button to begin your laundry cycle.

If That Didn't Work

• Perform a Hard Power Reset: If the buttons are unresponsive, the control board may be glitched. Unplug the washer from the 120V wall outlet entirely. While unplugged, press and hold the Power button for 15 seconds to drain the residual electricity from the capacitors on the main PCB. Plug the unit back in and attempt the button combination again.
• Check for Stuck Buttons: Inspect the Spin Speed and Soil Level buttons for any physical sticking or residue (like detergent buildup). If one button is physically jammed in the "pressed" position, the board cannot register the simultaneous press required to unlock the system. Use a damp microfiber cloth to clean around the edges of the buttons.
• Test the Door Latch Sensor: If the lock symbol persists but the Child Lock combination doesn't work, the machine may think the lid is open. Ensure the lid is fully closed and there is no clothing caught in the hinge. If the lid switch is faulty, the machine will stay in a locked state as a safety precaution, which can sometimes mimic the Child Lock display.
• Control Board Power Cycle: Turn the machine off via the power button, then flip the circuit breaker in your home's electrical panel for 5 minutes. This forces a deeper reset of the Samsung control logic than simply unplugging the cord.

Heads Up

• Avoid using aggressive chemical cleaners on the control panel, as liquid can seep under the buttons and cause "ghost presses" that trigger the Child Lock automatically.
• If you frequently trigger this mode, be mindful of where you place laundry baskets or detergent bottles on top of the machine, as leaning on the console can activate the lock.
• Regularly check that the lid is completely clear of debris; a malfunctioning lid sensor can lead to various "Lock" errors that are often mistaken for the Child Lock setting.
• If the "nd" code persists after unlocking and you are using an Auto-Dispense model, check your detergent reservoirs to ensure they are filled to the minimum line, as the machine may trigger a detergent alert once the lock is removed.